PC-Progress Discussion Forums

The quotation that you give is related to the direct module (i.e., h1d_calc.exe), which indeed allows you to have up to 100 observation nodes. It is not related to the inverse module (i.e., h1d_clci.exe), which allows you to have up to 10 observation nodes. And you are using the inverse module. J.

I have never worked, and hopefully never will, withLinux, and thus cannot help.

You should first try to run the test examples that come with the HYDRUS-1D installation to see whether the problem is with your input or with your compiled program.

J.

That's exactly what happens. There is no mass transfer if you have initially an equilibrium. Once water content increases, it dilutes concentration and mass transfer starts. J.

No. The mass transfer is nonzero only when there is non-equilibrium, i.e., when the liquid phase is not in equilibrium with the solid phase (see eq. 3.9). When the soil is dry, there is only very little solute mass in the liquid phase (at equilibrium) and the mass transfer can start only once water ...

Note that for non-equilibrium solute transport model, you need to specify the initial condition for the liquid phase concentration and for the kinetically sorbed concentration (concentration on Type-2 sites). While the former one is an equilibrium concentration and thus the equilibrium sorbed concen...

1. Yes. For Type=0 (cumulative flux), position=1 for the upper boundary and =2 for the bottom boundary.
2. Yes, observation nodes are numbered sequentially, starting from the top.

Note that you could easily find the answers in the examples distributed with the HYDRUS-1D software.

J.

If you are new to HYDRUS, you should read about rules on spatial and temporal discretization (FAQ :
http://www.pc-progress.com/Documents/No ... zation.pdf

J.

Getdat and Gettime are compiler-specific functions, which should be replaced. The Function RTime() uses data provided by these two function. You can find it in the file Time.for. J.

This seems to be something that should be quite clear from the simulated results, right?

If you select the option "Root Growth" in "Main Processes", then values calculated from "Root Growth Parameters" are used for rooting depth and values from the Meteo section are ignored.

J.

Potential ET is usually evaluated using models such as Penman-Monteith, Hargreaves, etc, from measured meteo data. See references given in the HYDRUS-1D manual: Monteith, 1981; Monteith and Unsworth, 1990; FAO, 1990; Hargreaves, 1994; and Jensen et al., 1997.

J.

I do not think that what you write is exactly true. Note that crop coefficients are small during early crop growth (much lower than 1). I.e., the crop coefficient is taking into account the reduction of potential evaporation to actual values, which HYDRUS does using the hCritA value. J.

Ashkan, It should be technically possible to do what you described using HYDRUS-1D (i.e., using both temperature and moisture data in the objective function). However, the information content of such data (e.g., temperatures) for the estimation of soil hydraulic properties for a given experimental s...

I think that the answer is obvious. The numerical model does not consider semi-infinite profile (as the analytical solution does); the soil profile is always finite and the boundary conditions are specified at a given locations and this BC affect the concentration profile in its near vicinity. If yo...

The solute transport part of HYDRUS-1D has been extensively and successfully tested against the analytical solutions from CFitm, CFitIm, and CXTFIT. Note that these analytical solutions are valid for different surface (Dirichlet or Cauchy) BCs, as well as for different bottom boundary conditions (fi...

The model does not have an option to select only some part of the season for triggered irrigation. If you want to do that, you need to split the simulation into multiple simulations, while importing results of preceding simulation as the initial condition of the subsequent simulation.

J.